Lifting-jack.



PATENTED MAR. 19, 19o?,v

L.o.HARA. LIFTING JACK.

' APPLIOATION FILED SEPT. 8, 1906.

UNITED STATES PATENT OFFICE.

LEWIS o HARA, or AUBURN, NEW YORK.

`|.||=1'|Nte-IN2K.

To all wil/bm it ma/ i/ concern.' l

Be it knownthat I, LEwIs O. HARA, a' citizen Iofthe United States, and aeresident of Auburn, in the county of Cayuga, in the State of New York, have invented new and useful Improvements in Lifting-Jacks, of

, which the following, taken in connection with the accompanying drawings, is a lull, clear, and exact description.

Thisy invention Ihas special reference to the species of lifting-jack. which hasv the paWl mounted on a horizontal pivotal support and tical.' channel, which may be 'either plain, as

engaging a disk ratchet which has itsI teeth` projecting from the top surface offthe disk,

as .shown inmy Letters Patent No. 317,951, dated May 12, 1885. In the said patent 4the pawl is pivoted directly on theleverof the jack, which lever is attached by means of a threaded lend portion of the lever screwed 'into a socket formed in the side of a collar embracing the screw.l In practice it is'found that the lever attached in said manner is liable to become loose in the socket and sag from its requisite horizontal position and also move out'of its radial positlon, and thus disarrange the pawlin relation to the ratchet. A further objection to thesaid construction of the jack is the detachment ofthe awl simultaneously with the detachment o vthe le. ver, and thus incurring the lability'of losing 'd the awl.,v y T e obijlect 'of my present` invention is tov obviate t e aforesaid defects' and objection able features of the lifting-jack; and to that end the invention consists in the improved construction and combination of parts hereinafte'r described, and illustrated inthe ac' companying drawings, in which- Flgure 1 is a side elevationofa lifting-jack embodying my invention. Fig. 2 is a vertical section of the same.

and Fig. 4 is a vertical section of a modificatiQn of my invention.

A represents the"base ofthe 'ack, the top portion of which baseis' forme with a vershown at a in Fig. 4, or screw-threaded, as

shown at a in Fig. 2. In the threaded channel a works the externallyfthreaded lower end portion of the main screw b, which. is hol'- low and screw-threaded internally, as shown at c, reverse from the externalthreads of lsaid screw and receives in it the auxiliary screw d.

4 'i lSpecification of Letters Patent. application mea september s, racc. l serai N9. 338.791.

Fig: 3 is a horizon-A tal transverse section-on the line a; m in Fig. 2,'

Patented marcnlQ, 1.907.

. The upper endportion of the screw 5 is of 5;

the form of. an-externally plain cylinder e, .terminatingin a'circmferential rim or iange f. Ata short distancefbelow the said a'nge is a horizontal disk ratchet g, fastened to the cylindrical port/ione of the screw `b by'aV set- 6o screw Lorothersuit'able means. Between tion ofthe steine, Whiclifis fastened therein preferably by rneans of a pin l, passing trans-J vers'ely through .the arm y' and stem l Into the 'Socke 1c-7s inserted the attachingL end of the lever mLWhich-isremovable without disturbing the' attachment ofthe alr'nV y" o lly connected to the stem ,by means of a s eve 0, embracing the shank and confined laterally by the end of the -armj and a shoulto the screw-b. mi representsa dufplex pawl .which is piv- 8o of said sleeve. v

, The component' lparts .of the described lifting-jack. are assembled by` lacing| the collar 71, o n the smooth upper e113 portion of the' screw b' and' fastening the rack' g. to the screwl immediately under the collar h, thenjinserting the lower vend of the -said screw into the threaded channel a of the base,

er ron the stem t, abutting against the ends y Into the'socket '7c is 'inserted the end por-f A.' The auxiliary screw d is then inserted into the main screw b. The' pawl n is ap-v plied tothe-stemf'. and-then retained thereon 95 by the insertion of said` shank into the-socket k ofthe arm j and fastening the stem therein. Finally the lever m is inserted into the socket kf of the arm j, and thus the jack is in condition to be operated by oscillation of the roo said lever, which in swinging in one direction causes the pawl nto engage the lrack g and. thereby turns the screw b., the engagement of which with the threaded portion a of the base causes the said screw to ascend and at 105 the same time the engagement of the internal -thread of the screw b with the auxiliary screw d forces the latter screw to travel up- "as shown at o, in the same manner as illusward in the screwib and thus accelerates th operation of the jack.- The pawl is duplex ro at s s". The. lower portion s is journaled-.in

. a" plain vertical channel a in the top portion.

4of the base A, and the upper portion s is loosely embraced bythe collar h, which has integral with it the ra'dial horizontally-extending stem on which the pawl ispivoted,

trated in Fig. 2 of the drawings. v It'will be observed VAthat-in .each of the described 'constr'uctions ,the pawl is securely supported vand retained on the jack after the arm j has been removed, it merely re! quiring the pin l to be reinserted in thestemi.

What I claim as my invention is- The combination with the internallythreaded tubular screw receiving. through it the externally-threaded screw, and the disk ratchet rigidly attachedto said tubular screw and formed with upwardly-projecting teeth, of a collar loosely embracing the tubular screw above Athe disk-.ratchet and having a horizontal radiall -extending stem formed integral with it, t ev pawl formed with a sleeve embracing the stem adjacent to the collar, and an arm 'formed with a socket in one end receiving the end portion of the stem, a fastening-pin passing transversebT through said arm and stein, and a handle .detachablysecured to the opposite end of said arm substantially as set forth and LEWIS O. HARA. Witnesses:

M. K. DwYER," L J. U. LAAss.

v shown. 

